Which condition is most likely to cause excessive fluctuations of the pressure gauge in a hydraulic system?

Excessive fluctuations of the pressure gauge in a hydraulic system are most commonly caused by an inadequate supply of fluid. When the system does not have enough hydraulic fluid, several issues can arise. The fluid acts as a medium for transferring pressure, and insufficient fluid can lead to inconsistent pressure readings as the pump struggles to maintain the necessary flow and pressure.

With inadequate fluid, air can also enter the hydraulic lines, which disrupts the fluid’s ability to efficiently transmit pressure, leading to erratic gauge readings. This condition creates instability in the hydraulic system, making the pressure fluctuating and unreliable.

While excessive fluid pressure generally indicates a stable system, a damaged pressure gauge would simply provide inaccurate readings rather than fluctuating ones. Leaky hydraulic lines can lead to a loss of pressure but typically result in a more constant or steady drop rather than fluctuations in readings as the system is losing fluid consistently.